Diethyl acetylenedicarboxylate → ethyl 2-morpholino-7H-1,3,4-thiadiazolo-[3,2-a]-pyrimidin-7-one-5-carboxylate

HRID 1278323Notes

Reaction equation

HRID 1278323 reaction equation
[NH2:1][C:2]1[S:3][C:4]([N:7]2[CH2:12][CH2:11][O:10][CH2:9][CH2:8]2)=[N:5][N:6]=1.[C:13]([C:20](OCC)=[O:21])#[C:14][C:15]([O:17][CH2:18][CH3:19])=[O:16]>C(O)C>[O:10]1[CH2:9][CH2:8][N:7]([C:4]2[S:3][C:2]3=[N:1][C:20](=[O:21])[CH:13]=[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[N:6]3[N:5]=2)[CH2:12][CH2:11]1

Participants

4

Reactant 2

HCID 69803Diethyl acetylenedicarboxylateHCID 15000115-Morpholin-4-yl-1,3,4-thiadiazol-2-amine

Product 1

HCID 12899658ethyl 2-morpholino-7H-1,3,4-thiadiazolo-[3,2-a]-pyrimidin-7-one-5-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
60 °C

Procedure

3.5 g of the 2-amino-5-morpholino-1,3,4-thiadiazole obtained in Example 1 were mixed with 40 ml of absolute ethanol and then 3.2 g of diethyl acetylendicarboxylate was added. The reaction mixture was heated on a water bath to about 60° C. until a clear solution was formed. This was stored overnight at room temperature and then evaporated in vacuo to dryness. The residue was triturated with a small amount of cold ethanol, filtered off, washed with ether and finally dried. Thus 3.8 g, corresponding to 65.2% of the theoretical yield, of ethyl 2-morpholino-7H-1,3,4-thiadiazolo-[3,2-a]-pyrimidin-7-one-5-carboxylate, melting at 151° to 153° C., was obtained.

Workup

  1. customwas formed
  2. customevaporated in vacuo to dryness
  3. customThe residue was triturated with a small amount of cold ethanol
  4. filtrationfiltered off
  5. washwashed with ether
  6. customfinally dried

Sources & evidence

ORD record
ord-cfb7d1fb6bbf42dab03d6ffcd4d12a3a
Source dataset
uspto-grants-1981_07
Patent number
US04281120

Reaction notes

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